**4. Promise of natural product leads**

Since the early phase of the pandemics, many researchers have tried to examine bioactive compounds such as propolis and others, from natural products source as leads for SARS-CoV-2 drug candidates [39–47]. Although these efforts are still on going up to now, the leads are still in experimental stage in general. Several leads were developed with computational approaches from natural products, albeit still no conclusive experimental evidence that leads into clinical trials [48–51]. There is also effort for repurposing natural product leads, from H5N1 inhibitor lead compounds, that are yet to provide wet lab results [52]. One example of the lead compound with in silico potential for inhibiting SARS-CoV-2 is Juglanin, as visualized in **Figure 2**.

Computation of natural products chemistry is a way to leverage the indigenous knowledge with modern science such as bioinformatics and biomedicine [48, 54–63]. It has achieve certain success in medical application, such as the chemotherapy agent of Taxol [64, 65]. However, there is no standard natural product-based drug yet for COVID-19 up to now. In general, existing COVID-19 standard drugs are repurposed drugs that mainly comprises of synthetic and semi-synthetic compounds [66, 67]. How natural products bioactive compounds will perform in this domain, it remains to be seen.
